Page 204 - Industrial Cutting of Textile Materials

Fusing of cut textile components 191

pressure, and time–should be found for every fabric of the order, testing the fabric by
fusing presses, which will be used in the garment production process.

12.2.2.1 Fusing temperature
The temperature is the most important and the most critical factor for qualitative fusing.
It presents a heat required to melt the adhesive on the fabric surface. The temperature
has to be high enough to obtain high-quality fused composite and at the same time low
enough not to damage a base fabric of the interlining and a face fabric of the manufac-
tured garment. In the fusing process, there are two kinds of the ‘temperatures’ used:
The fusing temperature suggested by the interlining manufacturer.
●
The temperature read on the control panel of the fusing press.
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Often, the temperature showed on a control panel of the press is considered as the
temperature that is applied to the interlining. However, it is not so. The control panel
indicates the temperature of the conveyer belt, not the temperature of heat applied to
the interlining. The heat going through the fabric reduces, and the temperature reach-
ing the resin is lower (up to 30°C) than the belt temperature showed on the control
panel of the press. The heat reaching the fused components depends on the heating
time, the thickness, and the thermal conductivity of the fabrics and other factors.
The actual heat temperature applied to the resin of the interlining can be determined
only by the help of a test. The well-known paper measuring tapes are most suitable to
perform the temperature test. They are a kind of chemical reacting paper thermometers.
By fusing the fabric sample, this stripe has to be put between fabric and interlining.
After fusing, the fabric and the interlining have to be slightly torn apart in order to pull
the stripe out. The colour of the stripe shows the temperature that was on the fabric sur-
face. The paper stripes are very thin to allow a quick heating. The response time of the
indicator is less than 1 s. Accuracy of the measurement is at +/−1% of the printed val-
ues. Paper temperature measuring stripes are available in different temperature scales,
for example, for measuring 100–140°C, 130–170°C, 140–180°C, and 180–220°C.

12.2.3 Determination of fabric shrinkage
Fabric shrinkage often occurs during the fusing process, causing changes in the dimen-
sions of the cut and fused components. The extent of shrinkage for each fabric must
be predetermined throughout the sample making process. If its value is less than 1%,
the change of component dimensions may be ignored. If the shrinkage exceeds 1%,
the patterns of fusible components have to be corrected and the predictable shrinkage
amount added to their dimensions.
However, samples are not always made and tested from all fabrics (one style may be
designed for several fabrics), and the qualities of the face fabrics and interlinings used
to make samples may not conform to the materials delivered for production. Most often,
possible further problems (extensive shrinkage can prevent the joining of fused fabric
components with other parts of the garment) are prevented by adding fabric allowances
(buffers) around fusible components or their blocks in markers (see Fig. 12.1) and per-
forming two-step cutting. In the first step, the fusible components or their blocks are